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%I #38 Apr 16 2022 16:46:08
%S 2,76,122,422,2300,5090,7166,58046,91382,234178,314738
%N Numbers k such that k^9 + 9^k is prime.
%C Numbers k such that A185277(k) is prime.
%H Hans Havermann, <a href="http://chesswanks.com/num/a094133.txt">Indices of A094133 in A076980</a>.
%H Andrey V. Kulsha, <a href="http://www.primefan.ru/xyyxf/primes.html">Factorizations of x^y + y^x for 1 < y < x < 151</a>.
%H P. Leyland, <a href="http://www.leyland.vispa.com/numth/primes/xyyx.htm">Primes and Strong Pseudoprimes of the form x^y + y^x</a>.
%e 2 is a term of the sequence, because A185277(2) = 593 is prime.
%o (PARI) is(n) = ispseudoprime(n^9+9^n)
%Y Cf. A064539, A185277, A253471.
%K nonn,hard,more
%O 1,1
%A _Felix Fröhlich_, Aug 27 2016
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